InigoMontoya

With the exception of the automated target recognition aspect, what's being proposed has been actively studied by the military for the past ten years that I'm aware of. Not much new here

Late to the thread but the answer to this question that I've always liked is thus.... Anyone can build a bridge that stands, but it takes an engineer to build a bridge that *barely* stands.

1. Any background you would be willing to provide to prove I didn't just make a person up to question: A name to call you by (worded this way intentionally), job title, company, and what is your prior education and work experience? Call me, Inigo Montoya, of course. If you don't like that, pick one out of the phone book. Job Title: Aerospace Engineer. Company: DoD. Prior Education: BSME. Prior work experience: Nothing relevant. Been working for the DoD with the same job title for almost 20 years now. 'Twere my first job out of college and still my only job since college. 2. Describe a typical day for you in this career. I get into the office about 0645. I check email or maybe go to some meeting or another until maybe 0800 or 0900. I head out to the field to see what my guys are working on and/or how it's progressing. I eat lunch at 1100ish. I then spend the afternoon either helping with said projects or blowing stuff up, depending upon my schedule. I get back to the office about 1600, check email again, maybe do some design work, and go home at 1645-1700. 3. What do you enjoy the most/find the most interesting about this career? I am given the freedom and authority to explore out of the box ideas even if I'm the only person who thinks it'll work. 4. What is the least enjoyable aspect of this career? Red tape. 5. What skills/knowledge are most often used in a typical day within this career? Thermodynamics. Newtonian Physics. Statics/Dynamics. Chemistry. Materials Science. Basic Electrical Circuits. Compressible Flow. Knowledge of explosives in general and many weapon systems. I'm an expert in none of the those, but I use all of them on a regular basis. What's the expression? "I'm a jack of all trades, but a master of none." 6. Why did you decide on this particular career and employer, and are your expectations for it based on this satisfied now? When I was 6 years old I saw a video of a missile blowing up a tank. Not Hollywood; the real deal. Right then and there I knew what I wanted to do with my life, but unlike most 6 year old kids, I held true to the dream. Employer? That was as much chance as anything; could have been someone else. And 6 year old me would be thrilled with 40 year old me. 7. Are there any educational/work decisions you would change, or additional steps you would have taken towards your career path now? I would have dropped out of high school at age 16 and gone to college 2 years early. I consider high school to be the single biggest waste of my life. Having a bachelors at 20 would have been pretty cool. 8. Is there any advice you would give to someone considering a career in aerospace engineering, including additional education, preparation, or natural skills that you would deem necessary? You just have to have a decent head on your shoulders and what I like to refer to as, "The Love." 9. What would you suggest for succeeding within this career's job market? What did your employer seem to value the most? Be a damned good engineer and a leader of men. That's what my employer values. Were I only one of those two and not both, I would not be where I am today. As for how to lead (since that isn't something generally taught), I do so by example. I've never asked one of my crew to do anything I wasn't willing to do myself... And yes, I've swept many a floor and scrubbed a few toilets on the job. I make a point of doing such mundane tasks from time to time. It keeps me humble and sends a message to my crew that none of us are above the lowest job; it''s ALL important. 10. What would you suggest for successful networking (should I attend seminars, etc.) if networking is important and applicable in this career? Dunno what to tell ya there. The conferences I attend are by invitation only.

Which would you like? The unrealistic answer or the realistic answer? You can't have both. That said, the only realistic answer suitable for large scale has already been mentioned: Get people used to living like those in the 1800s did.

About as far away as your average cow is from actually jumping over the Moon.

And you presume to get around the law of conservation of energy.... exactly... how? (Oh, and magnetic repulsion using permanent magnets would work just as well to slow the whole schebang down... in other words, it doesn't solve the problem.)

On a sufficiently small scale and for sufficiently short periods of time I don't see a problem. The thought experiment for me is.... Control volume with precisely 2 atoms in it. It would be nice to get all atoms on one side of the volume. Just by chance, 25% of the time you're going to meet that "more ordered" condition. But that doesn't mean you can keep it up indefinitely or that the idea scales well.

Especially true given that in many areas, gas pipes aren't pipes in the normal sense... They're plastic tubes.

Ummm.... A toggle switch?

And how would you contain the plasma while you were shooting if towards the enemy? IE, why wouldn't it just result in a ball o' fire around your muzzle? How would you "reach out" with it? Also, what are the energy requirements to have a usable quantity of it? I mean, I can run my fingers through a candle flame without getting hurt. It's not enough to be merely hot, you have to have enough thermal mass to actually bring the temperature of your target up high enough to hurt it. That means high energy requirements. You want to make this solar powered?? So how big do you envision the solar panel being? Oh, and yes, laser weapons exist.

Re = ratio of inertial forces to viscous forces.... So you're going to get a very low number anytime you're moving very slowly through a very viscous fluid. I don't see how you'd ever get a negative value.

Stress = Load / Area Strain = E * Stress Those two equations, properly applied give you the second two problems.

Sorry, not gonna do your homework for you.

OK, more information required.... How large is the pressure vessel? When you say 100 C, is that the ambient temperature of the environment or just what's inside the pressure vessel? Budget? What are we trying to protect? IE, what's right next to the pressure vessel? People? Equipment? Why can't it be conductive?

Spectra (UHMWPE) comes immediately to mind provided you don't have high temperature requirements.

Work = mgh = 3500*9.8*1.2 = 41.16 kJ Time = 3.5 s. 41.16 kJ/ 3.5 s = 11.76 kW. Nothing's ever perfect without losses and such so I'd buy a 15 kW hydraulic pump. I know, not what you asked for, but it's what the real world wants to know.

Ok, so what is h and how does it differ from L?

My first thought was that the equation was for a cylinder on it's side, but before I even went to check the math I find myself confused..... What is this "shell" you're speaking of? Do we get any more context? I'm guessing we have a language barrier here....

Ion thrusters are very efficient, but they have terrible thrust/weight ratios. Cutting to the important part.... They can't even generate enough thrust to lift *themselves* off the ground, let alone a payload. They're great once you're *IN* space, but they're utterly worthless when it comes to getting you *TO* space. The bigger point being that there's more to a "good rocket" than efficiency. Thrust to weight ratio matters. Availability of materials matters. Environmental impact matters. Lots o' things matter.

When I asked about feeding I meant air supply, but now seeing you're talking about BB guns? Energy requirements just got easy. As for the QEVs, you can get a 3/4" QEV from McMaster-Carr for on the order of $20. Since you're going with such small projectiles, you could probably get away with a 3/8" valve... I'm guessing, but cost will probably be like $15.

Well, there are many variables, but I've a gun that uses a QEV and standard shop air (120 psi) to shoot golf balls at 600 fps (180 m/s). Rate of fire is another one that has many variables. How are you feeding it? But 60 rounds/min should be totally doable. Note: I'm assuming that your "60 rounds per second" mentioned in your original post is a typo. The power requirements for such a system get to be a bit on the insane side for any gun of non-negligible muzzle energy. [Re: The drawing] If I understand your drawings correctly... Again, if you want to do it just to say that you did, more power to ya. But if you want a gun with decent performance, you're barking up the wrong tree. You're chasing the $10 solution to a $2 problem.

Yeah, I admit that I take "alternative technology projectile propulsion" to an extreme.

Is this something that you want to do simply because you CAN do it? If so, knock yourself out. But understand that it would be MUCH easier and much less complicated to build a simple air gun using a QEV or similar valve, solenoid valves, an air compressor, and a small amount of automation. It would still be quite the little project, but it would perform to your stated requirements, be a lot easier to design, and insanely cheaper.

And given that it would be a new art, there WOULD be instances of performing the task badly.

Oooooo.... OK, so after I get home from vacation... Need to look into the foamglas and the aerogels.